BLACK-THROATED DIVER. 327 



Family COLYMBID^E. Genus COLYMBUS. 



BLACK-THROATED DIVER. 



COLYMBUS ARCTICUS, Linnaus. 



Single Brooded. Laying season, latter half of May, and in 

 June. 



BRITISH BREEDING AREA : The Black-throated Diver 

 is a much rarer and more local species than the pre- 

 ceding, nevertheless it is known to breed in various parts 

 of the Outer Hebrides, and on the mainland from Argyll, 

 through the counties of Inverness, Ross, and Sutherland, 

 to Caithness. It has not yet been known to breed in 

 Ireland, and is only a winter visitor to England. 



BREEDING HABITS : This Diver very closely resembles 

 the preceding species in its habits and economy. It is 

 a resident in our islands, but subject to considerable 

 local and southern movement during autumn and winter. 

 Its breeding-haunts are wild and secluded moorland 

 and mountain lochs, pools, and tarns, preference being 

 shown for such that contain islands. The Black-throated 

 Diver is not a gregarious species during the nesting 

 season, but several pairs may frequently be found within 

 a comparatively small area, each, however, keeping to 

 themselves and to one particular haunt. It is probable 

 that this Diver also pairs for life, and shows much at- 

 tachment to certain nesting-places. The nest, invariably 

 made upon the ground, is generally placed at no great 

 distance from the water's edge on an island, more or 

 less covered with grass and other coarse vegetation. It 

 is, however, usually made on the bare shingly beach 

 rather than amongst the herbage. This nest is rather 

 more substantial than that of the Red-throated Diver, 

 a mass of stalks, roots, and drifted aquatic vegetable 



